This invention relates to machine tool pre-setting, and, more particularly, to an apparatus and method for the positional adjustment of cutting tools for use on machine tools.
In automatic, repetitive machining operations, it is highly desirable to reduce the machine tool down time during such operations, resulting from, for example, the necessity to replace worn or broken cutting tools. Also, modern computer controlled machines such as lathes and machining centers are called upon to perform a wide range of operations, thus switching from one set of cutting tools necessary for one group of operations to a new set of cutting tools for a second, different group of operations necessitates machine down time.
One well known and recognized problem in adjusting and accurately fixing internal cutting tools such as drills, reamers, and boring tools in the tool holder or turret of, for example, a computer numerically controlled lathe (CNC lathe) is the absence of any readily available means for locating the end or cutting tip of the cutting tool in the same position repeatedly. Thus replacing worn or broken tools requires performing new setting-up operations for each tool, and each time the operation is changed, new setting up must be performed.
Normally, in a typical setting up operation, each tool is first adjusted by sight to something approximating its proper setting and is then brought down to a datum surface, which can be the bed of the machine, in order to determine the arbitrary position of that tool and enter its value into the computer that controls the machinery tool in question. This operation is time consuming, and must be performed for each cutting tool. It can be seen that replacing a worn or broken tool requires that this setting up operation be performed, thus holding the machine out of operation. Such replacement of tools, when done on an individual basis, produces an extreme amount of non-productive down time. Likewise, when the machine is switched to a second group of operations, the setting up procedure must be performed on each tool, resulting in an inordinate amount of idle time for the machine.